Need Help With 82 C10 A/C Vacuum Lines.

[mitchell lowery]

I have an 82 C10 With factory ac. The problem im having is im loosing a lot of my air through the vent that points at the transmission tunnel. The Defrost door inside the vent will not open so i checked my vacuum supply line from under the hood and it is connected and is getting vacuum to the vent controller behind the dash. but when i pulled the vacuum line off the defrost doors vacuum diaphragm thing it will not pull vacuum on any setting even thought the main vacuum line is pulling vacuum. this lead me to believe the switch that controls the flow of vacuum pressure on the Climate control unit is bad. Any tips or help would be greatly appreciated because i cannot find where to buy that vacuum switch anywhere other than getting a whole new climate control unit. The little yellow box in the picture i posted is what i believe is bad, This is a pic i found online. mine is much dirtier.

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[Craig 85]

I had a similar issue with my '85 recently. All my vacuum pods worked, but none of the vents worked correctly. The '85 has a different style of vacuum switch, but its been about of production for years. I had to buy a complete NOS control unit to fix the issue.

My last truck was a '79 K15. I was able to find the white valve on ebay, about 4-5 years ago for about $75. I believe it was a 9 port. Look for Camaros and similar vehicles. I believe that is what my listing was for.

Here' a number I just found on ebay. ACDelco 15-71518 / GM470333. Get ready to pay though.

This guy will rebuild yours.
http://thepartguy.com/ac-controls-chevytruck.htm

 

[mitchell lowery]

I had a similar issue with my '85 recently. All my vacuum pods worked, but none of the vents worked correctly. The '85 has a different style of vacuum switch, but its been about of production for years. I had to buy a complete NOS control unit to fix the issue.

My last truck was a '79 K15. I was able to find the white valve on ebay, about 4-5 years ago for about $75. I believe it was a 9 port. Look for Camaros and similar vehicles. I believe that is what my listing was for.

Here' a number I just found on ebay. ACDelco 15-71518 / GM470333. Get ready to pay though.

This guy will rebuild yours.
http://thepartguy.com/ac-controls-chevytruck.htm

Thanks for the info. Just curious if replacing that part fixed your problem? I wouldnt mind spending a little money on it if i knew it would fix the issue. as of right now im not getting enough air blowing on me to keep me cool on hot days.

 

[mitchell lowery]

Thanks for the info. Just curious if replacing that part fixed your problem? I wouldnt mind spending a little money on it if i knew it would fix the issue. as of right now im not getting enough air blowing on me to keep me cool on hot days.

I think i may just try and take it apart again and clean it all and grease it on the little orange pad that controls routing of vacuum. i already took it apart earlier today and nothing looked broken or out of place. just a little old and the pad maybe a little dried out but i put it all back together because it was getting dark and i need to take off trash tomorrow...

 

[Craig 85]

On both of my trucks replacing the valve fixed the problem. I did verify all 4 vacuum pods worked first and made sure none of my vacuum lines related to the A/C system had leaks. I also changed all the seals within the A/C too.

 

[mitchell lowery]

On both of my trucks replacing the valve fixed the problem. I did verify all 4 vacuum pods worked first and made sure none of my vacuum lines related to the A/C system had leaks. I also changed all the seals within the A/C too.

Craig, I appreciate you going out of your way to help me out and give me links to where the part could be found and verifying the symptoms im having with what you have previously experienced. I just wanted to give an update on the situation for anyone else who experiences this issue. i ended up just prying the vacuum switch thing apart with a flat head screw driver (Cracked a few spots around the edges but no big deal, Just watch out because there is a very small spring inside.) and took all the pieces and let them all soak in a small container with warm water and dish soap then scrubbed out all the dirt and grime with a small plastic bristle brush after they soaked for about an hour. then i put a small amount of grease on the small orange pad where the channels are to redirect vacuum pressure to help it seal any leaks and greased the slide rail it rides on. (you will see what i mean if you take it apart) but anyways i put everything back together and fired up the truck and now all modes are working including defrost. i could watch the door move all the way shut so it worked like a charm! Just Didnt wanna leave anyone hanging that may read this down the road because its happened to me many times and i havent personally found much info on this little part. But once again thank you for the help craig!

 

[Craig 85]

No problem. I tried that on the one for my '85, but it was too far done. Glad you got away with a cheap fix.

 

[Bill Yetman]

hello, I am in a similar situation as above. when I got the truck the lines were all disconnected and I had to replace the vacuum lines because they were dried out or broken. I couldn't find a replacement boot with the lines so I am trying to connect vacuum lines directly to the controller. the issue I am having is I cannot find a diagram of where the lines connect to on the controller. does anyone know where I can find a diagram? the truck does have A/C the controller I have is the same as the above picture
Thanks
Bill

 

[chengny]

hello, I am in a similar situation as above. when I got the truck the lines were all disconnected and I had to replace the vacuum lines because they were dried out or broken. I couldn't find a replacement boot with the lines so I am trying to connect vacuum lines directly to the controller. the issue I am having is I cannot find a diagram of where the lines connect to on the controller. does anyone know where I can find a diagram? the truck does have A/C the controller I have is the same as the above picture
Thanks
Bill

Not exactly sure what the "boot" is. But if by that you mean the connector on the end of the vacuum harness, I suppose it would be possible to attach each hose directly to the nipples on the control valve.

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Keep in mind that the OP was regarding the control valve for a 1982 system. Yours may look similar but has significant differences. There are 7 hoses that will have to be connected to (what looks like) 13 ports. This should be what your valve looks like:

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It has different mounting tabs as well:

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It might be a tedious process to determine which hose goes to which port and which ports are vents - but it can be done. Good luck.

BTW - the vacuum harness and associated connector were never available as replacement parts.

 

[Bill Yetman]

Thanks
the boot I referred to is the connector with the lines on it. The controller I have does not have the red electrical connector...will that be an issue?

Thanks
Bill

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[Craig 85]

I know my '79 had one similar to yours. I was wondering if you could put some shrink tubing over the nipples to take up some of the space in your old connector to prevent vacuum leaks?

 

[Bill Yetman]

The vacuum lines I have fit tight over the nipples. It looks like the power line and layout is different from mine and I am not sure if it will work

 

[chengny]

Thanks
the boot I referred to is the connector with the lines on it. The controller I have does not have the red electrical connector...will that be an issue?

Thanks
Bill

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Nah - that orange lead is meant to be connected to the HI speed terminal of the blower control switch. That terminal is a siamese type with two tabs.

When the mode control lever is in the MAX AC position, a pair of contacts within the selector switch close. Full battery voltage is then supplied to one of the two tabs on the HI terminal of the blower speed control switch. This design effectively takes blower speed control away from the operator (only while in MAX AC) and forces the fan to only run at high speed.

Without that lead attached to the blower switch, at MAX AC you will still have the ability to run the fan at all speeds.

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Its starting to seem as if someone has modified the original system - at least on the cab side.

 

[Bill Yetman]

oh yes...there are so many things done including no vin number on the cab so I do not know what year it is I do know the chassis is a 77 I was told the cab is a 86 but I found out it couldn't be because the wiper switch is on the dash so I am thinking its 81-83. the only thing that was in the cab when I got it was the light switch, wiper switch, a mess of wiring and the A/C heater control switch. I am trying yo get a dash harness with the correct wiring... USA 1 industries is looking into it, I need the power windows and locks and A/C but that's another issue...lol getting the vacuum lines to work properly is my issue now, I cant seam to find a diagram with my control switch. the diagram shown above has a different layout. I wonder if the numbers on the nipples would be the same for each type, my controller has 9 and the other one has about 13?

 

[Craig 85]

I'm in the process of painting the interior of my truck and I found a date code on top of the ashtray assembly dated "10 84." My truck was built 11/84. Maybe that will help figure out what year cab you have.

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